4 This driver implement the ACPI Extensions For Display Adapters for
5 integrated graphics devices on motherboard, as specified in ACPI 2.0
6 Specification, Appendix B, allowing to perform some basic control like
7 defining the video POST device, retrieving EDID information or to
8 setup a video output, etc. Note that this is an ref. implementation
9 only. It may or may not work for your integrated video device.
11 Interfaces exposed to userland through /proc/acpi/video:
13 VGA/info : display the supported video bus device capability like Video ROM, CRT/LCD/TV.
14 VGA/ROM : Used to get a copy of the display devices' ROM data (up to 4k).
15 VGA/POST_info : Used to determine what options are implemented.
16 VGA/POST : Used to get/set POST device.
17 VGA/DOS : Used to get/set ownership of output switching:
18 Please refer ACPI spec B.4.1 _DOS
22 VGA/*/brightness : Used to get/set brightness of output device
24 Notify event through /proc/acpi/event:
26 #define ACPI_VIDEO_NOTIFY_SWITCH 0x80
27 #define ACPI_VIDEO_NOTIFY_PROBE 0x81
28 #define ACPI_VIDEO_NOTIFY_CYCLE 0x82
29 #define ACPI_VIDEO_NOTIFY_NEXT_OUTPUT 0x83
30 #define ACPI_VIDEO_NOTIFY_PREV_OUTPUT 0x84
32 #define ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS 0x82
33 #define ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS 0x83
34 #define ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS 0x84
35 #define ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS 0x85
36 #define ACPI_VIDEO_NOTIFY_DISPLAY_OFF 0x86